Scheduled feed

ABSTRACT

Embodiments described herein generally provide for the scheduled feeding of cells in a cell expansion system. A schedule to proactively and automatically increase and/or maintain inlet rates of media to feed cells may be created, in which inlet rates to the intracapillary portion (or extracapillary portion) of a bioreactor may be increased or maintained according to the schedule. Such schedule may be conservative or aggressive or a combination thereof, for example. Multiple schedules may be used. Scheduled media exchanges may also be included. By following a feed schedule, the monitoring of metabolite levels may be optional. Inlet rates may be increased or maintained without manual manipulation. Media usage may also be more predictable. In an embodiment, a custom task(s) may be created to follow a desired feed schedule. In another embodiment, a pre-programmed task(s) may be used for the scheduled feeding of cells.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a divisional application of, and claims priority to, U.S. patent application Ser. No. 14/865,222, entitled, “Scheduled Feed,” filed on Sep. 25, 2015, which claims priority to, and the benefit of, U.S. Provisional Application Ser. No. 62/055,986, filed on Sep. 26, 2014, and entitled, “Scheduled Feed.” The disclosures of the above-identified applications are hereby incorporated by reference in their entireties as if set forth herein in full for all that they teach and for all purposes.

BACKGROUND

Cell Expansion Systems (CESs) are used to expand and differentiate cells. Cell expansion systems may be used to expand, e.g., grow, stem cells, such as mesenchymal stem cells (MSCs). Cell expansion systems may also expand other types of cells, such as bone marrow cells, for example. Stem cells which are expanded from donor cells may be used to repair or replace damaged or defective tissues and have broad clinical applications for a wide range of diseases. Cells, of both adherent and non-adherent type, may be grown in a bioreactor in a cell expansion system.

SUMMARY

Embodiments of the present disclosure generally relate to scheduled feeding systems and methods for a cell expansion system, in which schedules proactively and automatically increase or maintain inlet rates, e.g., intracapillary (IC) inlet rates or extracapillary (EC) inlet rates, into a circulation loop, e.g., IC circulation loop, in the cell expansion system. Such proactive and automatic feeding occurs according to the applicable schedule and regardless of metabolite levels during cell, e.g., MSC, expansions. In embodiments, media exchanges are also included as a part of such schedules, in which media is exchanged at a certain rate (and quantity) as defined by the schedule. Other feeding methods for cell expansion systems rely on the regular, e.g., daily, monitoring of metabolites, e.g., glucose and lactate from glucose consumption and lactate generation by the cells, to determine if inlet rates, e.g., IC inlet rates, should be increased. By instead following feed schedules, the taking of regular, e.g., daily, measurements of metabolites to determine whether or not to increase media inlet rates, e.g., IC inlet rates, may be optional or eliminated altogether, according to embodiments. Scheduled feeding and/or scheduled media exchanges may apply to the expansion of any type of cell.

Embodiments of the present disclosure further relate to aggressive and conservative feed schedules, in which an aggressive feed schedule feeds the cells at a faster rate (with a larger quantity of media used) than a conservative feed schedule, for example. In other embodiments, such schedule may maintain feeding rates at current levels and/or may increase feeding rates in a manner that is neither conservative nor aggressive but, instead, is a combination of the two, for example. In yet other embodiments, other types of feeding schedules may be used. In embodiments, these feed schedules are used in a closed, automated system for cell expansion.

In an embodiment, multiple schedules are used to expand cells in a particular run. In another embodiment, a single schedule is used for controlling the feeding of the cells during cell expansion in a particular run. In further embodiments, a single schedule may be used to control inlet rates for feeding the cells and for media exchanges, in which a media exchange replaces a portion or all of the existing media in a disposable set with new media. In other embodiments, one or more schedules may be used to control inlet rates for feeding the cells with one or more additional schedules used to control media exchanges.

Embodiments of the present disclosure provide for implementing such schedule(s) through the use of one or more protocols or tasks for use with a cell expansion system. Through a user interface (UI) and graphical user interface (GUI) elements, a custom or user-defined protocol or task for following a scheduled feed may be created. A task may comprise one or more steps. In other embodiments, a pre-programmed, default, or otherwise previously saved task for following a scheduled feed may be selected.

As used herein, “at least one,” “one or more,” and “and/or” are open-ended expressions that are both conjunctive and disjunctive in operation. For example, each of the expressions “at least one of A, B and C,” “at least one of A, B, or C,” “one or more of A, B, and C,” “one or more of A, B, or C” and “A, B, and/or C” means A alone, B alone, C alone, A and B together, A and C together, B and C together, or A, B and C together.

This Summary is included to provide a selection of concepts in a simplified form, in which such concepts are further described below in the Detailed Description. This Summary is not intended to be used in any way to limit the claimed subject matter's scope. Features, including equivalents and variations thereof, may be included in addition to those provided herein.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the present disclosure may be described by referencing the accompanying figures. In the figures, like numerals refer to like items.

FIG. 1A depicts an embodiment of a cell expansion system (CES).

FIG. 1B illustrates a front elevation view of an embodiment of a bioreactor showing circulation paths through the bioreactor.

FIG. 1C depicts a rocking device for moving a cell growth chamber rotationally or laterally during operation of a cell expansion system, according to embodiments of the present disclosure.

FIG. 2 illustrates a perspective view of a cell expansion system with a premounted fluid conveyance device, in accordance with embodiments of the present disclosure.

FIG. 3 depicts a perspective view of a housing of a cell expansion system, in accordance with embodiments of the present disclosure.

FIG. 4 illustrates a perspective view of a premounted fluid conveyance device, in accordance with embodiments of the present disclosure

FIG. 5 depicts a schematic of a cell expansion system, in accordance with an embodiment of the present disclosure.

FIG. 6 illustrates a schematic of a cell expansion system, in accordance with another embodiment of the present disclosure.

FIG. 7A depicts a flow diagram illustrating the operational characteristics of a process for implementing a feed schedule during a cell expansion, in accordance with embodiments of the present disclosure.

FIG. 7B illustrates a flow diagram depicting the operational characteristics of a process for implementing a feed schedule during a cell expansion, in accordance with embodiments of the present disclosure.

FIG. 8 depicts a flow diagram illustrating the operational characteristics of a process for implementing a task or protocol for a scheduled feeding of cells for use with a cell expansion system, in accordance with embodiments of the present disclosure.

FIG. 9 illustrates an example processing system of a cell expansion system upon which embodiments of the present disclosure may be implemented.

FIG. 10 depicts data of an example in accordance with an embodiment of the present disclosure.

FIG. 11 illustrates data of an example in accordance with an embodiment of the present disclosure.

FIG. 12 depicts data of an example in accordance with an embodiment of the present disclosure.

FIG. 13 illustrates data of an example in accordance with an embodiment of the present disclosure.

DETAILED DESCRIPTION

The following Detailed Description provides a discussion of illustrative embodiments with reference to the accompanying drawings. The inclusion of specific embodiments herein should not be construed as limiting or restricting the present disclosure. Further, while language specific to features, acts, and/or structures, for example, may be used in describing embodiments herein, the claims are not limited to the features, acts, and/or structures described. A person of skill in the art will appreciate that other embodiments, including improvements, are within the spirit and scope of the present disclosure. Further, any alternatives or additions, including any listed as separate embodiments, may be used or incorporated with any other embodiments herein described.

Embodiments of the present disclosure are generally directed to systems and methods for using scheduled media inlet rate increases or scheduled feeds, e.g., intracapillary (IC) inlet rate increases or extracapillary (EC) inlet rate increases, to expand cells in a cell expansion system. In embodiments, such cell expansion system is a closed, automated system. Feed schedules may be used to proactively and automatically increase IC inlet rates regardless of metabolite levels during cell, e.g., MSC, expansions. Scheduled feedings and/or scheduled media exchanges may apply to the expansion of any type of cell. By following the schedules, the taking of regular, e.g., daily, measurements of metabolites to determine whether or not to increase IC inlet rates may be optional or eliminated altogether, according to embodiments. Media usage may also be more predictable in embodiments. According to yet other embodiments, the schedule may provide for maintaining the inlet rate. With scheduled feeding, inlet rates may be increased or maintained without manual manipulation. For example, the inlet rates may increase and then level off or plateau, in which the schedule provides both for the increasing and the maintaining of the rates. In other embodiments, a first schedule provides for the increasing of the inlet rates, and a second schedule provides for the maintaining of the inlet rates at a certain rate. In embodiments, the first schedule is different from the second schedule. Additional schedules, such as third, fourth, fifth, sixth, seventh, etc. schedules may be used according to yet further embodiments.

Embodiments are directed to a cell expansion system, as noted above. In embodiments, such cell expansion system is closed, in which a closed cell expansion system comprises contents that are not directly exposed to the atmosphere. Such cell expansion system may be automated. In embodiments, cells, of both adherent and non-adherent type, may be grown in a bioreactor in the cell expansion system. According to embodiments, the cell expansion system may include base media or other type of media. Methods for replenishment of media are provided for cell growth occurring in a bioreactor of the closed cell expansion system. In embodiments, the bioreactor used with such systems is a hollow fiber bioreactor. Many types of bioreactors may be used in accordance with embodiments of the present disclosure.

The system may include, in embodiments, a bioreactor that further includes a first fluid flow path having at least opposing ends, a first opposing end of the first fluid flow path fluidly associated with a first port of a hollow fiber membrane and a second end of the first fluid flow path fluidly associated with a second port of the hollow fiber membrane, in which the first fluid flow path comprises an intracapillary portion of the hollow fiber membrane. In embodiments, a hollow fiber membrane comprises a plurality of hollow fibers. The system may further include a fluid inlet path fluidly associated with the first fluid flow path, in which a plurality of cells are introduced into the first fluid flow path through a first fluid inlet path. A first pump for circulating fluid in the first fluid flow path of the bioreactor may also be included. In embodiments, the system includes a controller for controlling operation of the first pump. In an embodiment, the controller is a computing system, including a processor, for example. The controller is configured, in embodiments, to control the pump to circulate a fluid at a first rate within the first fluid flow path. In some embodiments, a second pump for transferring intracapillary inlet fluid from an intracapillary media bag to the first fluid flow path and a second controller for controlling operation of the second pump are included. The second controller, in embodiments, controls the second pump to transfer cells from a cell inlet bag to the first fluid flow path, for example. Additional controllers, e.g., third controller, fourth controller, fifth controller, sixth controller, etc., may be used in accordance with embodiments. Further, additional pumps, e.g., third pump, fourth pump, fifth pump, sixth pump, etc., may be used in accordance with embodiments of the present disclosure. In addition, while the present disclosure may refer to a media bag, a cell inlet bag, etc., multiple bags, e.g., a first media bag, a second media bag, a third media bag, a first cell inlet bag, a second cell inlet bag, a third cell inlet bag, etc., and/or other types of containers, may be used in embodiments. In other embodiments, a single media bag, a single cell inlet bag, etc., may be used. Further, additional or other fluid paths, e.g., a second fluid flow path, a second fluid inlet path, etc., may be included in embodiments.

In other embodiments, the system is controlled by, for example: a processor coupled to the cell expansion system; a display device, in communication with the processor, and operable to display data; and a memory, in communication with and readable by the processor, and containing a series of instructions. In embodiments, when the instructions are executed by the processor, the processor receives an instruction to coat the bioreactor, for example. In response to the instruction to coat the bioreactor, the processor may execute a series of steps to coat the bioreactor and may next receive an instruction to load cells into the bioreactor, for example. In response to the instruction to load cells, the processor may execute a series of steps to load the cells from a cell inlet bag, for example, into the bioreactor.

A schematic of an example cell expansion system (CES) is depicted in FIG. 1A, in accordance with embodiments of the present disclosure. CES 10 includes first fluid circulation path 12 and second fluid circulation path 14. First fluid flow path 16 has at least opposing ends 18 and 20 fluidly associated with a hollow fiber cell growth chamber 24 (also referred to herein as a “bioreactor”), according to embodiments. Specifically, opposing end 18 may be fluidly associated with a first inlet 22 of cell growth chamber 24, and opposing end 20 may be fluidly associated with first outlet 28 of cell growth chamber 24. Fluid in first circulation path 12 flows through the interior of hollow fibers 116 (see FIG. 1B) of hollow fiber membrane 117 (see FIG. 1B) disposed in cell growth chamber 24 (cell growth chambers and hollow fiber membranes are described in more detail infra). Further, first fluid flow control device 30 may be operably connected to first fluid flow path 16 and may control the flow of fluid in first circulation path 12.

Second fluid circulation path 14 includes second fluid flow path 34, cell growth chamber 24, and a second fluid flow control device 32. The second fluid flow path 34 has at least opposing ends 36 and 38, according to embodiments. Opposing ends 36 and 38 of second fluid flow path 34 may be fluidly associated with inlet port 40 and outlet port 42 respectively of cell growth chamber 24. Fluid flowing through cell growth chamber 24 may be in contact with the outside of hollow fiber membrane 117 (see FIG. 1B) in the cell growth chamber 24, in which a hollow fiber membrane comprises a plurality of hollow fibers. Second fluid circulation path 14 may be operably connected to second fluid flow control device 32.

First and second fluid circulation paths 12 and 14 may thus be separated in cell growth chamber 24 by a hollow fiber membrane 117 (see FIG. 1B). Fluid in first fluid circulation path 12 flows through the intracapillary (“IC”) space of the hollow fibers in the cell growth chamber 24. First circulation path 12 may be referred to as the “IC loop.” Fluid in second circulation path 14 flows through the extracapillary (“EC”) space in the cell growth chamber 24. Second fluid circulation path 14 may be referred to as the “EC loop.” Fluid in first fluid circulation path 12 may flow in either a co-current or counter-current direction with respect to flow of fluid in second fluid circulation path 14, according to embodiments.

Fluid inlet path 44 may be fluidly associated with first fluid circulation path 12. Fluid inlet path 44 allows fluid into first fluid circulation path 12, while fluid outlet path 46 allows fluid to leave CES 10. Third fluid flow control device 48 may be operably associated with fluid inlet path 44. Alternatively, third fluid flow control device 48 may alternatively be associated with first outlet path 46.

Fluid flow control devices as used herein may comprise a pump, valve, clamp, or combination thereof, according to embodiments. Multiple pumps, valves, and clamps can be arranged in any combination. In various embodiments, the fluid flow control device is or includes a peristaltic pump. In embodiments, fluid circulation paths, inlet ports, and outlet ports may be constructed of tubing of any material.

Various components are referred to herein as “operably associated.” As used herein, “operably associated” refers to components that are linked together in operable fashion and encompasses embodiments in which components are linked directly, as well as embodiments in which additional components are placed between the two linked components. “Operably associated” components can be “fluidly associated.” “Fluidly associated” refers to components that are linked together such that fluid can be transported between them. “Fluidly associated” encompasses embodiments in which additional components are disposed between the two fluidly associated components, as well as components that are directly connected. Fluidly associated components can include components that do not contact fluid, but contact other components to manipulate the system (e.g., a peristaltic pump that pumps fluids through flexible tubing by compressing the exterior of the tube).

Generally, any kind of fluid, including buffers, protein containing fluid, and cell-containing fluid, for example, can flow through the various circulations paths, inlet paths, and outlet paths. As used herein, “fluid,” “media,” and “fluid media” are used interchangeably.

Turning to FIG. 1B, an example of a hollow fiber cell growth chamber 100 which may be used with the present disclosure is shown in front side elevation view. Cell growth chamber 100 has a longitudinal axis LA-LA and includes cell growth chamber housing 104. In at least one embodiment, cell growth chamber housing 104 includes four openings or ports: IC inlet port 108, IC outlet port 120, EC inlet port 128, and EC outlet port 132.

According to embodiments of the present disclosure, fluid in a first circulation path enters cell growth chamber 100 through IC inlet port 108 at a first longitudinal end 112 of the cell growth chamber 100, passes into and through the intracapillary side (referred to in various embodiments as the intracapillary (“IC”) side or “IC space” of a hollow fiber membrane) of a plurality of hollow fibers 116 comprising hollow fiber membrane 117, and out of cell growth chamber 100 through IC outlet port 120 located at a second longitudinal end 124 of the cell growth chamber 100. The fluid path between the IC inlet port 108 and the IC outlet port 120 defines the IC portion 126 of the cell growth chamber 100. Fluid in a second circulation path flows in the cell growth chamber 100 through EC inlet port 128, comes in contact with the extracapillary side or outside (referred to as the “EC side” or “EC space” of the membrane) of the hollow fibers 116, and exits cell growth chamber 100 via EC outlet port 132. The fluid path between the EC inlet port 128 and the EC outlet port 132 comprises the EC portion 136 of the cell growth chamber 100. Fluid entering cell growth chamber 100 via the EC inlet port 128 may be in contact with the outside of the hollow fibers 116. Small molecules (e.g., ions, water, oxygen, lactate, etc.) may diffuse through the hollow fibers 116 from the interior or IC space of the hollow fiber to the exterior or EC space, or from the EC space to the IC space. Large molecular weight molecules, such as growth factors, are typically too large to pass through the hollow fiber membrane, and may remain in the IC space of the hollow fibers 116. The media may be replaced as needed, in embodiments. Media may also be circulated through an oxygenator or gas transfer module to exchange gasses as needed. Cells may be contained within a first circulation path and/or a second circulation path, as described below, and may be on either the IC side and/or EC side of the membrane, according to embodiments.

The material used to make the hollow fiber membrane 117 may be any biocompatible polymeric material which is capable of being made into hollow fibers. One material which may be used is a synthetic polysulfone-based material, according to an embodiment of the present disclosure. In order for the cells to adhere to the surface of the hollow fibers, the surface may be modified in some way, either by coating at least the cell growth surface with a protein such as fibronectin or collagen, or by exposing the surface to radiation, according to embodiments. Gamma treating the membrane surface allows for attachment of adherent cells without additionally coating the membrane with fibronectin, cryoprecipitate, or the like. Bioreactors made of gamma treated membranes may be reused. Other coatings and/or treatments for cell attachment may be used in accordance with embodiments of the present disclosure.

In embodiments, the CES (such as CES 500 (see FIG. 5 ) and/or CES 600 (see FIG. 6 ), for example) may include a device configured to move or “rock” the cell growth chamber relative to other components of the cell expansion system by attaching it to a rotational and/or lateral rocking device. FIG. 1C shows one such device, in which a bioreactor 100 may be rotationally connected to two rotational rocking components and to a lateral rocking component, according to an embodiment.

A first rotational rocking component 138 rotates the bioreactor 100 around central axis 142 of the bioreactor 100. Rotational rocking component 138 may be rotationally associated with bioreactor 100. In embodiments, bioreactor 100 may be rotated continuously in a single direction around central axis 142 in a clockwise or counterclockwise direction. Alternatively, bioreactor 100 may rotate in alternating fashion, first clockwise, then counterclockwise, for example, around central axis 142, according to embodiments.

The CES may also include a second rotational rocking component that rotates bioreactor 100 around rotational axis 144. Rotational axis 144 may pass through the center point of bioreactor 100 and may be normal to central axis 142. Bioreactor 100 may be rotated continuously in a single direction around rotational axis 144 in a clockwise or counterclockwise direction, in embodiments. Alternatively, bioreactor 100 may be rotated around rotational axis 144 in an alternating fashion, first clockwise, then counterclockwise, for example. In various embodiments, bioreactor 100 may also be rotated around rotational axis 144 and positioned in a horizontal or vertical orientation relative to gravity.

In embodiments, lateral rocking component 140 may be laterally associated with bioreactor 100. The plane of lateral rocking component 140 moves laterally in the −x and −y directions, in embodiments. The settling of cells in the bioreactor may be reduced by movement of cell-containing media within the hollow fibers, according to embodiments.

The rotational and/or lateral movement of a rocking device may reduce the settling of cells within the device and reduce the likelihood of cells becoming trapped within a portion of the bioreactor. The rate of cells settling in the cell growth chamber is proportional to the density difference between the cells and the suspension media, according to Stoke's Law. In certain embodiments, a 180 degree rotation (fast) with a pause (having a total combined time of 30 seconds, for example) repeated as described above keeps non-adherent red blood cells suspended. A minimum rotation of about 180 degrees would be preferred in an embodiment; however, one could use rotation of up to 360 degrees or greater. Different rocking components may be used separately, or may be combined in any combination. For example, a rocking component that rotates bioreactor 100 around central axis 142 may be combined with the rocking component that rotates bioreactor 100 around axis 144. Likewise, clockwise and counterclockwise rotation around different axes may be performed independently in any combination.

Turning to FIG. 2 , an embodiment of a cell expansion system 200 with a premounted fluid conveyance assembly is shown in accordance with embodiments of the present disclosure. The CES 200 includes a cell expansion machine 202 that comprises a hatch or closable door 204 for engagement with a back portion 206 of the cell expansion machine 202. An interior space 208 within the cell expansion machine 202 includes features adapted for receiving and engaging a premounted fluid conveyance assembly 210. The premounted fluid conveyance assembly 210 is detachably-attachable to the cell expansion machine 202 to facilitate relatively quick exchange of a new or unused premounted fluid conveyance assembly 210 at a cell expansion machine 202 for a used premounted fluid conveyance assembly 210 at the same cell expansion machine 202. A single cell expansion machine 202 may be operated to grow or expand a first set of cells using a first premounted fluid conveyance assembly 210 and, thereafter, may be used to grow or expand a second set of cells using a second premounted fluid conveyance assembly 210 without needing to be sanitized between interchanging the first premounted fluid conveyance assembly 210 for the second premounted fluid conveyance assembly 210. The premounted fluid conveyance assembly 210 includes a bioreactor 100 and an oxygenator or gas transfer module 212 (also see FIG. 4 ). Tubing guide slots are shown as 214 for receiving various media tubing connected to premounted fluid conveyance assembly 210, according to embodiments.

Next, FIG. 3 illustrates the back portion 206 of cell expansion machine 202 prior to detachably-attaching a premounted fluid conveyance assembly 210 (FIG. 2 ), in accordance with embodiments of the present disclosure. The closable door 204 (shown in FIG. 2 ) is omitted from FIG. 3 . The back portion 206 of the cell expansion machine 202 includes a number of different structures for working in combination with elements of a premounted fluid conveyance assembly 210. More particularly, the back portion 206 of the cell expansion machine 202 includes a plurality of peristaltic pumps for cooperating with pump loops on the premounted fluid conveyance assembly 210, including the IC circulation pump 218, the EC circulation pump 220, the IC inlet pump 222, and the EC inlet pump 224. In addition, the back portion 206 of the cell expansion machine 202 includes a plurality of valves, including the IC circulation valve 226, the reagent valve 228, the IC media valve 230, the air removal valve 232, the cell inlet valve 234, the wash valve 236, the distribution valve 238, the EC media valve 240, the IC waste valve 242, the EC waste valve 244, and the harvest valve 246. Several sensors are also associated with the back portion 206 of the cell expansion machine 202, including the IC outlet pressure sensor 248, the combination IC inlet pressure and temperature sensors 250, the combination EC inlet pressure and temperature sensors 252, and the EC outlet pressure sensor 254. Also shown is an optical sensor 256 for an air removal chamber, according to an embodiment.

In accordance with embodiments, a shaft or rocker control 258 for rotating the bioreactor 100 is shown. Shaft fitting 260 associated with the shaft or rocker control 258 allows for proper alignment of a shaft access aperture, see e.g., 424 (FIG. 4 ) of a tubing-organizer, see e.g., 300 (FIG. 4 ) of a premounted conveyance assembly 210 or 400 with the back portion 206 of the cell expansion machine 202. Rotation of shaft or rocker control 258 imparts rotational movement to shaft fitting 260 and bioreactor 100. Thus, when an operator or user of the CES 200 attaches a new or unused premounted fluid conveyance assembly 400 (FIG. 4 ) to the cell expansion machine 202, the alignment is a relatively simple matter of properly orienting the shaft access aperture 424 (FIG. 4 ) of the premounted fluid conveyance assembly 210 or 400 with the shaft fitting 260.

Turning to FIG. 4 , a perspective view of a detachably-attachable premounted fluid conveyance assembly 400 is shown. The premounted fluid conveyance assembly 400 may be detachably-attachable to the cell expansion machine 202 (FIGS. 2 and 3 ) to facilitate relatively quick exchange of a new or unused premounted fluid conveyance assembly 400 at a cell expansion machine 202 for a used premounted fluid conveyance assembly 400 at the same cell expansion machine 202. As shown in FIG. 4 , the bioreactor 100 may be attached to a bioreactor coupling that includes a shaft fitting 402. The shaft fitting 402 includes one or more shaft fastening mechanisms, such as a biased arm or spring member 404 for engaging a shaft, e.g., 258 (shown in FIG. 3 ), of the cell expansion machine 202.

According to embodiments, the premounted fluid conveyance assembly 400 includes tubing 408A, 408B, 408C, 408D, 408E, etc., and various tubing fittings to provide the fluid paths shown in FIGS. 5 and 6 , as discussed below. Pump loops 406A and 406B may also be provided for the pump(s). In embodiments, although the various media may be provided at the site where the cell expansion machine 202 is located, the premounted fluid conveyance assembly 400 may include sufficient tubing length to extend to the exterior of the cell expansion machine 202 and to enable welded connections to tubing associated with media bag(s) or container(s), according to embodiments.

Next, FIG. 5 illustrates a schematic of an embodiment of a cell expansion system 500, and FIG. 6 illustrates a schematic of another embodiment of a cell expansion system 600. In the embodiments shown in FIGS. 5 and 6 , and as described below, the cells are grown in the IC space. However, the disclosure is not limited to such examples and may in other embodiments provide for cells to be grown in the EC space.

FIG. 5 illustrates a CES 500, which includes first fluid circulation path 502 (also referred to as the “intracapillary loop” or “IC loop”) and second fluid circulation path 504 (also referred to as the “extracapillary loop” or “EC loop”), according to embodiments. First fluid flow path 506 may be fluidly associated with cell growth chamber 501 to form first fluid circulation path 502. Fluid flows into cell growth chamber 501 through IC inlet port 501A, through hollow fibers in cell growth chamber 501, and exits via IC outlet port 501B. Pressure gauge 510 measures the pressure of media leaving cell growth chamber 501. Media flows through IC circulation pump 512 which may be used to control the rate of media flow. IC circulation pump 512 may pump the fluid in a first direction or second direction opposite the first direction. Exit port 501B may be used as an inlet in the reverse direction. Media entering the IC loop may enter through valve 514. As those skilled in the art will appreciate, additional valves, pressure gauges, pressure/temperature sensors, ports, and/or other devices may be placed at various locations to isolate and/or measure characteristics of the media along portions of the fluid paths. Accordingly, it is to be understood that the schematic shown represents one possible configuration for various elements of the CES 500, and modifications to the schematic shown are within the scope of the one or more present embodiments.

With regard to the IC loop 502, samples of media may be obtained from sample port 516 or sample coil 518 during operation. Pressure/temperature gauge 520 disposed in first fluid circulation path 502 allows detection of media pressure and temperature during operation. Media then returns to IC inlet port 501A to complete fluid circulation path 502. Cells grown/expanded in cell growth chamber 501 may be flushed out of cell growth chamber 501 into harvest bag 599 through valve 598 or redistributed within the hollow fibers for further growth.

Fluid in second fluid circulation path 504 enters cell growth chamber 501 via EC inlet port 501C, and leaves cell growth chamber 501 via EC outlet port 501D. Media in the EC loop 504 may be in contact with the outside of the hollow fibers in the cell growth chamber 501, thereby allowing diffusion of small molecules into and out of the hollow fibers.

Pressure/temperature gauge 524 disposed in the second fluid circulation path 504 allows the pressure and temperature of media to be measured before the media enters the EC space of the cell growth chamber 501, according to an embodiment. Pressure gauge 526 allows the pressure of media in the second fluid circulation path 504 to be measured after it leaves the cell growth chamber 501. With regard to the EC loop, samples of media may be obtained from sample port 530 or a sample coil during operation.

In embodiments, after leaving EC outlet port 501D of cell growth chamber 501, fluid in second fluid circulation path 504 passes through EC circulation pump 528 to oxygenator or gas transfer module 532. EC circulation pump 528 may also pump the fluid in opposing directions. Second fluid flow path 522 may be fluidly associated with oxygenator or gas transfer module 532 via oxygenator inlet port 534 and oxygenator outlet port 536. In operation, fluid media flows into oxygenator or gas transfer module 532 via oxygenator inlet port 534, and exits oxygenator or gas transfer module 532 via oxygenator outlet port 536. Oxygenator or gas transfer module 532 adds oxygen to, and removes bubbles from, media in the CES 500, for example. In various embodiments, media in second fluid circulation path 504 may be in equilibrium with gas entering oxygenator or gas transfer module 532. The oxygenator or gas transfer module 532 may be any appropriately sized oxygenator or gas transfer device. Air or gas flows into oxygenator or gas transfer module 532 via filter 538 and out of oxygenator or gas transfer device 532 through filter 540. Filters 538 and 540 reduce or prevent contamination of oxygenator or gas transfer module 532 and associated media. Air or gas purged from the CES 500 during portions of a priming sequence may vent to the atmosphere via the oxygenator or gas transfer module 532.

In the configuration depicted for CES 500, fluid media in first fluid circulation path 502 and second fluid circulation path 504 flows through cell growth chamber 501 in the same direction (a co-current configuration). The CES 500 may also be configured to flow in a counter-current conformation.

In accordance with at least one embodiment, media, including cells (from bag 562), and fluid media from bag 546 may be introduced to first fluid circulation path 502 via first fluid flow path 506. Fluid container 562 (e.g., Cell Inlet Bag or Saline Priming Fluid for priming air out of the system) may be fluidly associated with the first fluid flow path 506 and the first fluid circulation path 502 via valve 564.

Fluid containers, or media bags, 544 (e.g., Reagent) and 546 (e.g., IC Media) may be fluidly associated with either first fluid inlet path 542 via valves 548 and 550, respectively, or second fluid inlet path 574 via valves 570 and 576. First and second sterile sealable input priming paths 508 and 509 are also provided. An air removal chamber (ARC) 556 may be fluidly associated with first circulation path 502. The air removal chamber 556 may include one or more ultrasonic sensors including an upper sensor and lower sensor to detect air, a lack of fluid, and/or a gas/fluid interface, e.g., an air/fluid interface, at certain measuring positions within the air removal chamber 556. For example, ultrasonic sensors may be used near the bottom and/or near the top of the air removal chamber 556 to detect air, fluid, and/or an air/fluid interface at these locations. Embodiments provide for the use of numerous other types of sensors without departing from the spirit and scope of the present disclosure. For example, optical sensors may be used in accordance with embodiments of the present disclosure. Air or gas purged from the CES 500 during portions of the priming sequence or other protocols may vent to the atmosphere out air valve 560 via line 558 that may be fluidly associated with air removal chamber 556.

EC media (e.g., from bag 568) or wash solution (e.g., from bag 566) may be added to either the first or second fluid flow paths. Fluid container 566 may be fluidly associated with valve 570 that may be fluidly associated with first fluid circulation path 502 via distribution valve 572 and first fluid inlet path 542. Alternatively, fluid container 566 may be fluidly associated with second fluid circulation path 504 via second fluid inlet path 574 and EC inlet path 584 by opening valve 570 and closing distribution valve 572. Likewise, fluid container 568 may be fluidly associated with valve 576 that may be fluidly associated with first fluid circulation path 502 via first fluid inlet path 542 and distribution valve 572. Alternatively, fluid container 568 may be fluidly associated with second fluid inlet path 574 by opening valve 576 and closing distribution valve 572.

An optional heat exchanger 552 may be provided for media reagent or wash solution introduction.

In the IC loop, fluid may be initially advanced by the IC inlet pump 554. In the EC loop, fluid may be initially advanced by the EC inlet pump 578. An air detector 580, such as an ultrasonic sensor, may also be associated with the EC inlet path 584.

In at least one embodiment, first and second fluid circulation paths 502 and 504 are connected to waste line 588. When valve 590 is opened, IC media may flow through waste line 588 and to waste or outlet bag 586. Likewise, when valve 582 is opened, EC media may flow through waste line 588 to waste or outlet bag 586.

In embodiments, cells may be harvested via cell harvest path 596. Here, cells from cell growth chamber 501 may be harvested by pumping the IC media containing the cells through cell harvest path 596 and valve 598 to cell harvest bag 599.

Various components of the CES 500 may be contained or housed within a machine or housing, such as cell expansion machine 202 (FIGS. 2 and 3 ), wherein the machine maintains cells and media, for example, at a predetermined temperature.

Turning to FIG. 6 , a schematic of another embodiment of a cell expansion system 600 is shown. CES 600 includes a first fluid circulation path 602 (also referred to as the “intracapillary loop” or “IC loop”) and second fluid circulation path 604 (also referred to as the “extracapillary loop” or “EC loop”). First fluid flow path 606 may be fluidly associated with cell growth chamber 601 to form first fluid circulation path 602. Fluid flows into cell growth chamber 601 through IC inlet port 601A, through hollow fibers in cell growth chamber 601, and exits via IC outlet port 601B. Pressure sensor 610 measures the pressure of media leaving cell growth chamber 601. In addition to pressure, sensor 610 may, in embodiments, also be a temperature sensor that detects the media pressure and temperature during operation. Media flows through IC circulation pump 612 which may be used to control the rate of media flow. IC circulation pump 612 may pump the fluid in a first direction or second direction opposite the first direction. Exit port 601B may be used as an inlet in the reverse direction. Media entering the IC loop may enter through valve 614. As those skilled in the art will appreciate, additional valves, pressure gauges, pressure/temperature sensors, ports, and/or other devices may be placed at various locations to isolate and/or measure characteristics of the media along portions of the fluid paths. Accordingly, it is to be understood that the schematic shown represents one possible configuration for various elements of the CES 600, and modifications to the schematic shown are within the scope of the one or more present embodiments.

With regard to the IC loop, samples of media may be obtained from sample coil 618 during operation. Media then returns to IC inlet port 601A to complete fluid circulation path 602. Cells grown/expanded in cell growth chamber 601 may be flushed out of cell growth chamber 601 into harvest bag 699 through valve 698 and line 697. Alternatively, when valve 698 is closed, the cells may be redistributed within chamber 601 for further growth.

Fluid in second fluid circulation path 604 enters cell growth chamber 601 via EC inlet port 601C and leaves cell growth chamber 601 via EC outlet port 601D. Media in the EC loop may be in contact with the outside of the hollow fibers in the cell growth chamber 601, thereby allowing diffusion of small molecules into and out of the hollow fibers that may be within chamber 601, according to an embodiment.

Pressure/temperature sensor 624 disposed in the second fluid circulation path 604 allows the pressure and temperature of media to be measured before the media enters the EC space of the cell growth chamber 601. Sensor 626 allows the pressure and/or temperature of media in the second fluid circulation path 604 to be measured after it leaves the cell growth chamber 601. With regard to the EC loop, samples of media may be obtained from sample port 630 or a sample coil during operation.

After leaving EC outlet port 601D of cell growth chamber 601, fluid in second fluid circulation path 604 passes through EC circulation pump 628 to oxygenator or gas transfer module 632. EC circulation pump 628 may also pump the fluid in opposing directions, according to embodiments. Second fluid flow path 622 may be fluidly associated with oxygenator or gas transfer module 632 via an inlet port 632A and an outlet port 632B of oxygenator or gas transfer module 632. In operation, fluid media flows into oxygenator or gas transfer module 632 via inlet port 632A, and exits oxygenator or gas transfer module 632 via outlet port 632B. Oxygenator or gas transfer module 632 adds oxygen to, and removes bubbles from, media in the CES 600, for example. In various embodiments, media in second fluid circulation path 604 may be in equilibrium with gas entering oxygenator or gas transfer module 632. The oxygenator or gas transfer module 632 may be any appropriately sized device useful for oxygenation or gas transfer. Air or gas flows into oxygenator or gas transfer module 632 via filter 638 and out of oxygenator or gas transfer device 632 through filter 640. Filters 638 and 640 reduce or prevent contamination of oxygenator or gas transfer module 632 and associated media. Air or gas purged from the CES 600 during portions of a priming sequence may vent to the atmosphere via the oxygenator or gas transfer module 632.

In the configuration depicted for CES 600, fluid media in first fluid circulation path 602 and second fluid circulation path 604 flows through cell growth chamber 601 in the same direction (a co-current configuration). The CES 600 may also be configured to flow in a counter-current conformation, according to embodiments.

In accordance with at least one embodiment, media, including cells (from a source such as a cell container, e.g., a bag) may be attached at attachment point 662, and fluid media from a media source may be attached at attachment point 646. The cells and media may be introduced into first fluid circulation path 602 via first fluid flow path 606. Attachment point 662 may be fluidly associated with the first fluid flow path 606 via valve 664, and attachment point 646 may be fluidly associated with the first fluid flow path 606 via valve 650. A reagent source may be fluidly connected to point 644 and be associated with fluid inlet path 642 via valve 648, or second fluid inlet path 674 via valves 648 and 672.

Air removal chamber (ARC) 656 may be fluidly associated with first circulation path 602. The air removal chamber 656 may include one or more sensors including an upper sensor and lower sensor to detect air, a lack of fluid, and/or a gas/fluid interface, e.g., an air/fluid interface, at certain measuring positions within the air removal chamber 656. For example, ultrasonic sensors may be used near the bottom and/or near the top of the air removal chamber 656 to detect air, fluid, and/or an air/fluid interface at these locations. Embodiments provide for the use of numerous other types of sensors without departing from the spirit and scope of the present disclosure. For example, optical sensors may be used in accordance with embodiments of the present disclosure. Air or gas purged from the CES 600 during portions of a priming sequence or other protocol(s) may vent to the atmosphere out air valve 660 via line 658 that may be fluidly associated with air removal chamber 656.

An EC media source may be attached to EC media attachment point 668, and a wash solution source may be attached to wash solution attachment point 666, to add EC media and/or wash solution to either the first or second fluid flow path. Attachment point 666 may be fluidly associated with valve 670 that may be fluidly associated with first fluid circulation path 602 via valve 672 and first fluid inlet path 642. Alternatively, attachment point 666 may be fluidly associated with second fluid circulation path 604 via second fluid inlet path 674 and second fluid flow path 684 by opening valve 670 and closing valve 672. Likewise, attachment point 668 may be fluidly associated with valve 676 that may be fluidly associated with first fluid circulation path 602 via first fluid inlet path 642 and valve 672. Alternatively, fluid container 668 may be fluidly associated with second fluid inlet path 674 by opening valve 676 and closing distribution valve 672.

In the IC loop, fluid may be initially advanced by the IC inlet pump 654. In the EC loop, fluid may be initially advanced by the EC inlet pump 678. An air detector 680, such as an ultrasonic sensor, may also be associated with the EC inlet path 684.

In at least one embodiment, first and second fluid circulation paths 602 and 604 are connected to waste line 688. When valve 690 is opened, IC media may flow through waste line 688 and to waste or outlet bag 686. Likewise, when valve 692 is opened, EC media may flow to waste or outlet bag 686.

After cells have been grown in cell growth chamber 601, they may be harvested via cell harvest path 697. Here, cells from cell growth chamber 601 may be harvested by pumping the IC media containing the cells through cell harvest path 697, with valve 698 open, into cell harvest bag 699.

Various components of the CES 600 may be contained or housed within a machine or housing, such as cell expansion machine 202 (FIGS. 2 and 3 ), wherein the machine maintains cells and media, for example, at a predetermined temperature. It is further noted that, in embodiments, components of CES 600 and CES 500 (FIG. 5 ) may be combined. In other embodiments, a CES may include fewer or additional components than those shown in FIGS. 5 and 6 and still be within the scope of the present disclosure. An example of a cell expansion system that may incorporate features of the present disclosure is the Quantum® Cell Expansion System, manufactured by Terumo BCT, Inc. in Lakewood, Colo.

Examples and further description of cell expansion systems are provided in U.S. Pat. No. 8,309,347 (“Cell Expansion System and Methods of Use,” issued on Nov. 13, 2012), which is hereby incorporated by reference herein in its entirety for all that it teaches and for all purposes.

While various example embodiments of a cell expansion system and methods associated therewith have been described, FIG. 7A illustrates example operational steps 700 of a process for implementing a scheduled feed that may be used with a cell expansion system, such as CES 500 (FIG. 5 ) or CES 600 (FIG. 6 ), in accordance with embodiments of the present disclosure. In embodiments, such schedule may provide for one or more scheduled media exchange(s). START operation 702 is initiated, and process 700 proceeds to load the disposable tubing set 704 onto the cell expansion system. Next, the system may be primed 706. In an embodiment, a user or an operator, for example, may provide an instruction to the system to prime by selecting a task for priming, for example. In an embodiment, such task for priming may be a pre-programmed task. Process 700 then proceeds to coat the bioreactor 708, in which the bioreactor may be coated with a coating agent. For example, in embodiments, a reagent may be loaded into an IC loop until a reagent container is empty. The reagent may be chased from an air removal chamber into the IC loop, and the reagent may then be circulated in the IC loop. Any coating reagent known to those of skill in the art may be used, such as fibronectin or cryoprecipitate, for example. Once the bioreactor is coated, the IC/EC Washout task may be performed 710, in which fluid on the IC circulation loop and on the EC circulation loop is replaced. The replacement volume is determined by the number of IC Volumes and EC Volumes exchanged.

Next, to maintain the proper or desired gas concentration across the fibers in the bioreactor membrane, the condition media task 712 may be executed to allow the media to reach equilibrium with the provided gas supply before cells are loaded into the bioreactor. For example, rapid contact between the media and the gas supply provided by the gas transfer module or oxygenator is provided by using a high EC circulation rate. The system may then be maintained in a proper or desired state until a user or operator, for example, is ready to load cells into the bioreactor.

Process 700 next proceeds to loading cells 714 into the bioreactor from a cell inlet bag, for example. In an embodiment, the cells may be loaded into the bioreactor from the cell inlet bag until the bag is empty. Cells may then be chased from the air removal chamber to the bioreactor. In embodiments that utilize larger chase volumes, cells may be spread and move toward the IC outlet. The distribution of cells may be promoted across the membrane via IC circulation, such as through an IC circulation pump, with no IC inlet, for example. Further, the cells, e.g., adherent cells, may be allowed to attach 716 to the hollow fibers.

Next, process 700 proceeds to query 718, in which it is determined whether it is desired to follow a scheduled feed. If a scheduled feed is desired, process 700 branches “yes” to query 720 to determine whether a conservative, aggressive, or other type of scheduled feed is desired. Such schedules may be created by a custom task(s) for the cell expansion system, in which a user or an operator enters the desired feeding information and other conditions, such as media exchange(s), for example, according to an embodiment. In another embodiment, the schedule may be selected from a list of pre-programmed, default, or previously saved tasks. In embodiments, the task (e.g., custom, pre-programmed, default, etc.) also may define the bioreactor rotation, in which the bioreactor may be rotated at some point(s) during the attachment and expansion of the cells. For example, the bioreactor may be rotated 180°, or another defined degree of rotation, at a particular time(s) or point(s) in the cell expansion.

Where a conservative feed schedule is desired, process 700 follows the “conservative” branch to initiate a conservative feed schedule 722. The cells are then fed according to the conservative feed schedule 724, in which the cells may be fed with media. For example, the cells may be fed with complete media, according to an embodiment. Complete media may be any media source used for cell growth. In an embodiment, complete media may comprise alpha-MEM (α-MEM) and fetal bovine serum (FBS), for example. Any type of media known to those of skill in the art may be used. While FIG. 7A and process 700 refer to a conservative feed schedule at step 722, for example, embodiments provide for the use of a single or multiple conservative feed schedules. Thus, multiple conservative feed schedules may be initiated and followed for the feeding of the cells at steps 722 and 724. In other embodiments, a single conservative feed schedule may be followed.

In an embodiment, a conservative feed schedule, such as the following shown in Table 1, may be used:

TABLE 1 Example Conservative Feed Schedule Day Conservative Day 0 (Attach Cells) 0.1 mL/min EC Inlet Day 1 (Feed Cells) 0.1 mL/min IC Inlet Day 2 (Feed Cells) 0.2 mL/min IC Inlet Day 3 (Feed Cells) 0.3 mL/min IC Inlet Day 4 (Feed Cells) 0.5 mL/min IC Inlet Day 5 (Feed Cells) 0.8 mL/min IC Inlet Day 6 (Feed Cells) 1.0 mL/min IC Inlet or Harvest Day 7 (Feed Cells or 1.2 mL/min IC Inlet or Harvest) Harvest Estimated Media 4.4 L Usage (Calculated based on a 7-day expansion starting on Day 0 Attach Cells to Day 7 Harvest)

In embodiments, a range of inlet rates, or inlet flow rates, may be used during a conservative feed schedule. For example, in embodiments such as shown in Table 1, the inlet rates may range from about 0.01 mL/min IC (or EC) inlet to about 10.0 mL/min IC (or EC) inlet, with increases at each consecutive time period or interval, e.g., day or about 24-hour period, about 12-hour period, about 36-hour period, about 48-hour period, etc. In other embodiments, such as those involving a larger volume or growth space for cell expansion, inlet rates may range from about 100 mL/min to about 1,000 mL/min; about 2,000 mL/min; about 3,000 mL/min, etc. In consideration of the volume or growth space for cell expansion, any amounts for scheduled inlet rates, inlet rate increases (or decreases or maintenance amounts), and/or media exchanges may be used in accordance with embodiments of the present disclosure.

According to embodiments, the inlet rates may increase, for example, at each consecutive time period or interval, e.g., day or about 24-hour period, about 12-hour period, about 36-hour period, about 48-hour period, etc., according to a percentage of the previous time period's rate, e.g., an increase of about 1% to about 100% from the previous time period's rate. For example, the inlet flow rate may be increased by a percentage equal to or greater than about 1%, equal to or greater than about 5%, equal to or greater than about 10%, equal to or greater than about 15%, equal to or greater than about 20%, equal to or greater than about 25%, equal to or greater than about 30%, equal to or greater than about 35%, equal to or greater than about 40%, and equal to or greater than about 50%, of the previous time period's rate. In other embodiments, the inlet flow rate may be increased by a percentage less than or equal to about 55%, less than or equal to about 60%, less than or equal to about 65%, less than or equal to about 70%, less than or equal to about 75%, less than or equal to about 80%, less than or equal to about 85%, less than or equal to about 90%, and less than or equal to about 100%, of the previous time period's rate. In embodiments, the inlet rates may increase by the same or different percentages for particular periods or intervals of time in a linear or non-linear fashion. For example, as indicated in Table 1, a conservative feed schedule may include the doubling, i.e., increasing of the inlet rate by about 100%, of the inlet rate at Day 1 (or other time period) to achieve the inlet rate at Day 2 (or other time period), according to an embodiment. Next, the inlet rates may increase by a smaller percentage, such as about 50%, about 66.6%, about 60%, about 25%, about 20%, respectively, of the previous time period's rate for the remaining days, or time periods, until harvest, according to embodiments. In embodiments, a conservative feed schedule may provide for the increase, decrease, and/or maintenance of flow rates for different periods of time.

In embodiments, the inlet rates or inlet flow rates may be increased at fractions of a day or other period of time, e.g., after a certain number of hours or minutes has passed. For example, the inlet rates may be increased automatically at 12 hour intervals, 6 hour intervals, 3 hour intervals, 1 hour intervals, 30 minute increments, 15 minute increments, etc. In other embodiments, the inlet rates may be increased at intervals or periods spanning multiple days. For example, the inlet rates may be increased automatically at 1.5 day intervals, 2 day intervals, 3 day intervals, 4 day intervals, etc.

In an embodiment, the feeding of cells per a conservative feed schedule(s) 724 may proceed according to the example operational steps 754 depicted in FIG. 7B of a process for implementing a scheduled feed that may be used with a cell expansion system, such as CES 500 (FIG. 5 ) or CES 600 (FIG. 6 ). In embodiments, such scheduled feed may provide for one or more scheduled media exchange(s). Process 754 may be performed as one or more steps in process 700 (FIG. 7A). For example, process 754 may be performed as part of steps 724, 730, and/or 734 of process 700 (FIG. 7A). As shown in FIG. 7A, a number of steps may precede process 754, in embodiments. In other embodiments, additional, fewer, or different steps than those illustrated in process 700 (FIG. 7A) may precede process 754. Further, additional, fewer, or different steps may be included in process 754 than those shown in FIG. 7B. For example, additional steps may be performed following step 766, according to embodiments.

Turning to FIG. 7B and process 754, START operation 756 is initiated, and process 754 proceeds to feed the cells at a first inlet rate during a first time period or interval of time according to a schedule, e.g., conservative feed schedule, 758, according to an embodiment. Next, the first inlet rate may be increased, according to a schedule, by a first percentage of the first inlet rate to achieve a second inlet rate 760. Process 754 then proceeds to feed the cells at the second inlet rate during a second time period 762 according to a schedule. The second inlet rate may then be increased, according to a schedule, by a second percentage of the second inlet rate to achieve a third inlet rate 764. Process 754 then proceeds with feeding the cells, according to a schedule, at a third inlet rate during a third time period 766. Process 754 then terminates at END operation 768. While process 754 depicts a first time period, a second time period, and a third time period, there could be any number of time periods, e.g., a fourth time period, a fifth time period, a sixth time period, a seventh time period, etc., in embodiments. In addition, while process 754 depicts a first inlet rate, a second inlet rate, and a third inlet rate, there could be any number of inlet rates, e.g., a fourth inlet rate, a fifth inlet rate, a sixth inlet rate, a seventh inlet rate, etc., in embodiments.

Returning to FIG. 7A, the cells are allowed to grow or expand 726 while the conservative feed schedule is followed. The cells are not limited to growing or expanding at step 726, but, instead, the cells may also expand during the feeding step(s), for example. According to embodiments, glucose and lactate measurements do not need to be monitored, and inlet rates do not need to be manually increased, while the feed schedule is followed. However, in embodiments, data may optionally be collected if it is desired to monitor conditions before, during, or after a feed schedule is initiated, for example.

Returning to query 720, if an aggressive scheduled feed is desired, process 700 branches from query 720 to “aggressive” to initiate an aggressive feed schedule 728. While FIG. 7A and process 700 refer to an aggressive feed schedule at step 728, for example, embodiments provide for the use of a single or multiple aggressive feed schedules. Thus, multiple aggressive feed schedules may be initiated and followed for the feeding of the cells at steps 728 and 730. In other embodiments, a single aggressive feed schedule may be followed. Such schedule may be created by a custom task(s) or custom protocol(s) for the cell expansion system, in which a user or an operator enters the desired feeding information and other conditions, such as media exchange(s), for example, according to an embodiment. In another embodiment, the schedule may be selected from a list of pre-programmed, default, or previously saved tasks. In embodiments, the task (e.g., custom, pre-programmed, default, etc.) may also define the bioreactor rotation, in which the bioreactor may be rotated at some point(s) during the attachment and expansion of the cells. For example, the bioreactor may be rotated 180°, or another defined degree of rotation, at a particular time(s) or point(s) in the cell expansion.

The cells may then be fed according to the aggressive feed schedule 730, in which the cells may be fed with media. For example, the cells may be fed with complete media, according to an embodiment. Complete media may be any media source used for cell growth. In an embodiment, complete media may comprise alpha-MEM (a-MEM) and fetal bovine serum (FBS), for example. Any type of media known to those of skill in the art may be used.

In an embodiment, an aggressive feed schedule, such as the following shown in Table 2, may be used:

TABLE 2 Example Aggressive Feed Schedule Day Aggressive Day 0 (Attach Cells) 0.1 mL/min EC Inlet Day 1 (Feed Cells) 0.1 mL/min IC Inlet Day 2 (Feed Cells) 0.2 mL/min IC Inlet Day 3 (Feed Cells) 0.4 mL/min IC Inlet Day 4 (Feed Cells) 0.8 mL/min IC Inlet Day 5 (Feed Cells) 1.2 mL/min IC Inlet Day 6 (Feed Cells) 1.6 mL/min IC Inlet or Harvest Day 7 (Feed Cells or 2.0 mL/min IC Inlet or Harvest) Harvest Estimated Media 6.4 L Usage (Calculated based on a 7-day expansion starting on Day 0 Attach Cells to Day 7 Harvest)

In embodiments, a range of inlet rates, or inlet flow rates, may be used during an aggressive feed schedule. For example, in embodiments such as shown in Table 2, the inlet rates may range from about 0.01 mL/min IC (or EC) inlet to about 12.0 mL/min IC (or EC) inlet, with increases at each consecutive time period or interval, e.g., day or about 24-hour period, about 12-hour period, about 36-hour period, about 48-hour period, etc. In other embodiments, such as those involving a larger volume or growth space for cell expansion, inlet rates may range from about 100 mL/min to about 1,000 mL/min; about 2,000 mL/min; about 3,000 mL/min; about 4,000 mL/min; about 5,000 mL/min, etc. In consideration of the volume or growth space for cell expansion, any amounts for scheduled inlet rates, inlet rate increases (or decreases or maintenance amounts), and/or media exchanges may be used in accordance with embodiments of the present disclosure.

According to embodiments, the inlet rates may increase, for example, at each consecutive time period or interval, e.g., day or about 24-hour period, about 12-hour period, about 36-hour period, about 48-hour period, etc., according to a percentage of the previous time period's rate, e.g., an increase of about 1% to about 300% of the previous time period's rate. For example, the inlet flow rate may be increased by a percentage of equal to or greater than about 1%, equal to or greater than about 5%, equal to or greater than about 10%, equal to or greater than about 15%, equal to or greater than about 20%, equal to or greater than about 25%, equal to or greater than about 30%, equal to or greater than about 35%, equal to or greater than about 40%, and equal to or greater than about 50%, of the previous time period's rate. In other embodiments, the inlet flow rate may be increased by a percentage of less than or equal to about 55%, less than or equal to about 60%, less than or equal to about 65%, less than or equal to about 70%, less than or equal to about 75%, less than or equal to about 80%, less than or equal to about 85%, less than or equal to about 90%, less than or equal to about 100%, less than or equal to 125%, less than or equal to 150%, less than or equal to 175%, less than or equal to 200%, less than or equal to 225%, less than or equal to 250%, less than or equal to 275%, and less than or equal to 300%, of the previous time period's rate.

In embodiments, the inlet rates may increase by the same or different percentages for particular periods or intervals of time in a linear or non-linear fashion. For example, as indicated in Table 2, an aggressive feed schedule may provide for the doubling of the inlet rate, i.e., provide for increases in inlet rates of equal to or greater than about 100%, of the previous time period's inlet rate for several consecutive time periods, e.g., days or about 24-hour periods, according to an embodiment. For example, in an embodiment, an aggressive feed schedule may provide for increases in inlet rates of equal to or greater than about 100% of the previous time period's inlet rate for at least two consecutive time periods or intervals of time. For example, the cells may be fed at a first inlet rate during a first time period. During a second time period, the cells may be fed at a second inlet rate, in which the second inlet rate comprises an amount that is equal to or greater than about 100%, for example, of the first inlet rate. Next, the cells may be fed at a third inlet rate during a third time period, in which the third inlet rate comprises an amount that is equal to or greater than about 100%, for example, of the second inlet rate. After such feeding, the inlet rates may increase by a smaller percentage, such as about 50%, about 33.3%, about 25%, respectively, of the previous time period's rate for the remaining days, or time periods, until harvest, according to embodiments. In embodiments, an aggressive feed schedule may provide for the increase and/or the maintenance of flow rates for different periods of time. In further embodiments, a feed schedule, e.g., aggressive, conservative, or other, may provide for a decrease in net flow rate from the previous time period's flow rate.

In embodiments, the inlet rates or inlet flow rates may be increased at fractions of a day or other period of time, e.g., after a certain number of hours or minutes has passed. For example, the inlet rates may be increased automatically at 12 hour intervals, 6 hour intervals, 3 hour intervals, 1 hour interval, 30 minute increments, 15 minute increments, etc. In other embodiments, the inlet rates may be increased at intervals spanning multiple days. For example, the inlet rates may be increased automatically at about 1.5 day intervals, 2 day intervals, 3 day intervals, 4 day intervals, etc., according to embodiments.

In an embodiment, the feeding of cells per an aggressive feed schedule(s) 730 may proceed according to the example operational steps 754 depicted in FIG. 7B of a process for implementing a scheduled feed that may be used with a cell expansion system, such as CES 500 (FIG. 5 ) or CES 600 (FIG. 6 ). In embodiments, such schedule may provide for one or more scheduled media exchange(s). Process 754 may be performed as one or more steps in process 700 (FIG. 7A). For example, process 754 may be performed as part of steps 724, 730, and/or 734 of process 700 (FIG. 7A). As shown in FIG. 7A, a number of steps may precede process 754, in embodiments. In other embodiments, additional, fewer, or different steps than those illustrated in process 700 (FIG. 7A) may precede process 754. Further, additional, fewer, or different steps may be included in process 754 than those shown in FIG. 7B. For example, additional steps may be performed following step 766, according to embodiments.

Turning to FIG. 7B and process 754, START operation 756 is initiated, and process 754 proceeds to feed the cells at a first inlet rate during a first time period or interval of time according to a schedule, e.g., aggressive feed schedule, 758, according to an embodiment. Next, the first inlet rate may be increased, according to a schedule, by a first percentage of the first inlet rate to achieve a second inlet rate 760. Process 754 then proceeds to feed the cells at the second inlet rate during a second time period 762 according to a schedule. The second inlet rate may then be increased, according to a schedule, by a second percentage of the second inlet rate to achieve a third inlet rate 764. Process 754 then proceeds with feeding the cells, according to a schedule, at a third inlet rate during a third time period 766. Process 754 then terminates at END operation 768. While process 754 depicts a first time period, a second time period, and a third time period, there could be any number of time periods, e.g., a fourth time period, a fifth time, period, a sixth time period, a seventh time period, etc., in embodiments. In addition, while process 754 depicts a first inlet rate, a second inlet rate, and a third inlet rate, there could be any number of inlet rates, e.g., a fourth inlet rate, a fifth inlet rate, a sixth inlet rate, a seventh inlet rate, etc., in embodiments.

Returning to process 700, the cells are allowed to grow or expand 726 while the aggressive feed schedule is followed. The cells are not limited to growing or expanding at step 726, but, instead, the cells may also expand during the feeding step(s), for example. According to embodiments, glucose and lactate measurements do not need to be monitored, and inlet rates do not need to be manually increased, while the feed schedule is followed. However, in embodiments, data may optionally be collected if it is desired to monitor conditions before, during, or after a feed schedule is initiated, for example.

Returning to query 720, if another type of scheduled feed is desired, process 700 branches from query 720 to “other” to initiate an “other” type of feed schedule 732. For example, such schedule may maintain feeding rates at current levels, according to an embodiment. In another embodiment, such schedule may increase feeding rates in a manner that is neither conservative nor aggressive but, instead, is a combination of the two, for example. For example, an aggressive feed schedule or multiple aggressive feed schedules may be followed for certain periods or intervals of time, while a conservative feed schedule or multiple conservative feed schedules may be followed for other periods or intervals of time, according to embodiments. In other embodiments, a single feed schedule may be followed with such feed schedule being a combination of a conservative feed schedule and an aggressive feed schedule based on the inlet flow rate amounts. In yet other embodiments, other types of feeding schedules may be used. While FIG. 7A and process 700 refer to an “other” schedule at step 732, for example, embodiments provide for the use of a single or multiple “other” feed schedules. Thus, multiple “other” feed schedules may be initiated and followed for the feeding of the cells at steps 732 and 734. In other embodiments, a single “other” feed schedule may be followed.

Such “other” schedules may be created by a custom task(s) or custom protocol(s) for the cell expansion system, in which a user or operator, for example, may enter the desired feeding information, and other conditions, such as media exchanges, for example, according to an embodiment. In another embodiment, the schedule may be selected from a list of pre-programmed, default, or previously saved tasks. In embodiments, the task (e.g., custom, pre-programmed, default, etc.) may also define the bioreactor rotation, in which the bioreactor may be rotated at some point(s) during the attachment and expansion of the cells. For example, the bioreactor may be rotated 180°, or another defined degree of rotation, at a particular time(s) or point(s) in the cell expansion.

The cells may then be fed according to the “other” type of feed schedule 734, in which the cells may be fed with media. For example, the cells may be fed with complete media, according to an embodiment. Complete media may be any media source used for cell growth. In an embodiment, complete media may comprise alpha-MEM (a-MEM) and fetal bovine serum (FBS), for example. Any type of media known to those of skill in the art may be used. In an embodiment, the feeding of cells per an “other” feed schedule(s) 734 may proceed according to the example operational steps 754 depicted in FIG. 7B of a process for implementing a scheduled feed that may be used with a cell expansion system, such as CES 500 (FIG. 5 ) or CES 600 (FIG. 6 ). In embodiments, such scheduled feed may provide for one or more scheduled media exchange(s). Process 754 may be performed as one or more steps in process 700 (FIG. 7A). For example, process 754 may be performed as part of steps 724, 730, and/or 734 of process 700 (FIG. 7A). As shown in FIG. 7A, a number of steps may precede process 754, in embodiments. In other embodiments, additional, fewer, or different steps than those illustrated in process 700 (FIG. 7A) may precede process 754. Further, additional, fewer, or different steps may be included in process 754 than those shown in FIG. 7B, in embodiments. For example, additional steps may be performed following step 766, according to embodiments.

Turning to FIG. 7B and process 754, START operation 756 is initiated, and process 754 proceeds to feed the cells at a first inlet rate during a first time period or interval of time according to a schedule, e.g., “other” feed schedule, 758, according to an embodiment. Next, the first inlet rate may be increased, according to a schedule, by a first percentage of the first inlet rate to achieve a second inlet rate 760. Process 754 then proceeds to feed the cells at the second inlet rate during a second time period 762 according to a schedule. The second inlet rate may then be increased, according to a schedule, by a second percentage of the second inlet rate to achieve a third inlet rate 764. Process 754 then proceeds with feeding the cells, according to a schedule, at a third inlet rate during a third time period 766. Process 754 then terminates at END operation 768. While process 754 depicts a first time period, a second time period, and a third time period, there could be any number of time periods, e.g., a fourth time period, a fifth time, period, a sixth time period, a seventh time period, etc., in embodiments. In addition, while process 754 depicts a first inlet rate, a second inlet rate, and a third inlet rate, there could be any number of inlet rates, e.g., a fourth inlet rate, a fifth inlet rate, a sixth inlet rate, a seventh inlet rate, etc., in embodiments.

Returning to FIG. 7A, the cells are allowed to grow or expand 726 while the “other” type of feed schedule is followed. According to embodiments, glucose and lactate measurements do not need to be monitored, and inlet rates do not need to be manually increased, while the feed schedule is followed. However, in embodiments, data may optionally be collected if it is desired to monitor conditions before, during, or after a feed schedule is initiated, for example.

Returning to query 718, if it is not desired to follow a scheduled feed, process 700 proceeds “no” to initiate feeding cells 736, in which the media from a media bag, for example, is added to the cells to feed them. Next, glucose/lactate levels may be measured 738, in which a user or operator, for example, may measure such levels on a regular basis, e.g., daily, to determine any adjustment(s) to make to the feed amounts of media 740 based on the consumption and production of these metabolites. In another embodiment, such glucose/lactate measurements may be taken at random time periods, depending on the user's or operator's preference, for example. In embodiments, such glucose/lactate levels are measured by taking a sample from a sample coil or sample port, such as an EC sample port, of a cell expansion system. In other embodiments, such glucose/lactate levels are measured by taking a sample by splicing the IC loop of a cell expansion system using a sterile tubing welder, for example. The cells may be fed accordingly 740 in amounts that account for the glucose/lactate levels measured at step 738. For example, the IC inlet rate may be increased two-fold when the glucose value falls below 70 mg/dL, according to an embodiment. The cells are allowed to grow or expand 742. The cells are not limited to growing or expanding at step 742, but, instead, the cells may also expand during the feeding step(s), for example. Next, query 744 determines whether it is desired to continue the monitoring of the glucose/lactate levels. If it is desired to continue such monitoring to allow for adjustments to the feeding rates, process 700 proceeds “yes” to measure glucose/lactate levels 738, and process 700 proceeds again to the feeding of the cells accordingly 740 and the growing/expanding of the cells 742. If it is not desired to continue the monitoring of such glucose/lactate levels, process 700 proceeds “no” from query 744.

Following either from “no” at query 744 or from the growth or expansion of the cells 726, attached cells may be released 746 from the membrane of the bioreactor and suspended in the IC loop, for example. In embodiments, an IC/EC washout task in preparation for adding a reagent to release the cells is performed as part of operation 746. For example, IC/EC media may be replaced with a phosphate buffered saline (PBS) to remove protein, calcium (Ca²⁺), and magnesium (Mg²⁺) in preparation for adding trypsin, or another chemical-releasing agent, to release any adherent cells. A reagent may be loaded into the system until the reagent bag is empty. The reagent may be chased into the IC loop, and the reagent may be mixed within the IC loop. Following the release of any adherent cells, harvest operation 748 transfers the cells in suspension from the IC circulation loop, for example, including any cells remaining in the bioreactor, to a harvest bag(s) or container(s). Finally, the disposable set is unloaded 750 from the cell expansion system, and process 700 then terminates at END operation 752.

Next, FIG. 8 illustrates example operational steps 800 of a process for implementing a task(s) or protocol(s) for a scheduled feeding of cells for use with a cell expansion system, such as CES 500 (FIG. 5 ) or CES 600 (FIG. 6 ), in accordance with embodiments of the present disclosure. In embodiments, such scheduled feed may provide for one or more scheduled media exchange(s). START operation 802 is initiated, in which a disposable set may be loaded onto a cell expansion system, the set may be primed, a bioreactor may be coated, IC/EC washout may occur, media may be conditioned, cells may be loaded, and cells may be allowed to attach, for example. Next, process 800 proceeds to query 804 to determine whether it is desired to follow a scheduled feed. If it is desired to follow a scheduled feed, process 800 branches “yes” to query 806 to determine whether a pre-programmed, default, or previously saved task is available for a scheduled feed. If such a task is available, process 800 proceeds “yes” to select, or receive the selection of, the pre-programmed task to initiate scheduled feeding 808. The cells may then be fed according to the feed schedule defined in the pre-programmed, default, or previously saved task, in which the cells may be fed with media. For example, the cells may be fed with complete media, according to an embodiment. Complete media may be any media source used for cell growth. In an embodiment, complete media may comprise alpha-MEM (a-MEM) and fetal bovine serum (FBS), for example. Any type of media known to those of skill in the art may be used. According to embodiments, glucose and lactate measurements do not need to be monitored, and inlet rates do not need to be manually increased, while a feed schedule is followed. However, in embodiments, data may optionally be collected if it is desired to monitor conditions before, during, or after a feed schedule is initiated, for example. In embodiments, such pre-programmed, default, or previously saved task may include defined inlet rates, media exchanges, etc., and may include a defined stop condition(s). For example, such stop condition may be a time period, such as about 24 hours, 12 hours, 6 hours, 30 minutes, 36 hours, 48 hours, 72 hours, etc., according to embodiments. In an embodiment, the pre-programmed, default, or previously saved task may also define the bioreactor rotation, in which the bioreactor may be rotated at some point(s) during the attachment and expansion of the cells. For example, the bioreactor may be rotated 180°, or another defined degree of rotation, at a particular time(s) or point(s) in the cell expansion. The cells are allowed to grow or expand 810. The cells are not limited to growing or expanding at step 810, but, instead, the cells may also expand during the feeding step(s), for example.

If a pre-programmed, default, or previously saved task is not available, process 800 branches “no” from query 806 to create a custom task X for scheduled feeding 812, in which a user or operator, for example, may customize a task(s) to provide for the scheduled feeding of cells. In embodiments, such custom task may include defined inlet rates, media exchanges, etc., and may include a defined stop condition(s). For example, such stop condition may be a time period, such as about 24 hours, 12 hours, 6 hours, 30 minutes, 36 hours, 48 hours, 72 hours, etc., according to embodiments. In an embodiment, the custom task may also define the bioreactor rotation, in which the bioreactor may be rotated at some point(s) during the attachment and expansion of the cells. For example, the bioreactor may be rotated 180°, or another defined degree of rotation, at a particular time(s) or point(s) in the cell expansion.

Next, query 814 determines whether any other or additional custom tasks are desired. For example, step 812 may provide for creating Custom Task 1 for Day 1 (or other time period) of a scheduled feed, while step 814 may determine whether additional tasks, such as Custom Task 2 for Day 2 (or other time period), Custom Task 3 for Day 3 (or other time period), etc., are desired. Each custom task may thus be part of an overall schedule for feeding the cells, according to embodiments, in which each custom task itself provides for a scheduled feeding of the cells for a particular segment or interval of the schedule, e.g., time period (depending on any stop condition(s), for example). In other embodiments, a single custom task comprises multiple steps, or sub-tasks, to provide for each segment of a scheduled feeding, in which each step or sub-task comprises a defined inlet rate(s), stop condition(s), etc. In an embodiment, a custom task is created by modifying a previously defined task, such as a Feed Cells task, and saving the modified Feed Cells task as a new custom task for a scheduled feed. In another embodiment, a custom task may be created with new fields defined for the particular custom task desired.

Returning to query 814, if an additional custom task(s) is desired, process 800 proceeds “yes” to create custom task X for scheduled feeding 812. If no additional custom tasks are desired, process 800 proceeds “no” to select, or receive the selection of, the custom task X 815. Next, the custom task X for scheduled feeding is initiated 816, in which a first custom task may be initiated and may run until an applicable stop condition is met. The cells may then be fed according to the feed schedule defined in the custom task(s), in which the cells may be fed with media. For example, the cells may be fed with complete media, according to an embodiment. Complete media may be any media source used for cell growth. In an embodiment, complete media may comprise alpha-MEM (a-MEM) and fetal bovine serum (FBS), for example. Any type of media known to those of skill in the art may be used. According to embodiments, glucose and lactate measurements do not need to be monitored, and inlet rates do not need to be manually increased, while a feed schedule is followed. However, in embodiments, data may optionally be collected if it is desired to monitor conditions before, during, or after a feed schedule is initiated, for example. If additional custom tasks are present, such as a second custom task, third custom task, fourth custom task, etc., each successive custom task may start when the immediately prior custom task meets its stop condition. The cells are allowed to grow or expand 810. The cells are not limited to growing or expanding at step 810, but, instead, the cells may also expand during the feeding step(s), such as during the running of custom task X controlling inlet rates, etc., for example.

Following the growth or expansion of the cells 810, attached cells may be released 828 from the membrane of the bioreactor and suspended in the IC loop, for example. In embodiments, an IC/EC washout task in preparation for adding a reagent to release the cells is performed as part of operation 828. For example, IC/EC media may be replaced with a phosphate buffered saline (PBS) to remove protein, calcium (Ca²⁺), and magnesium (Mg²⁺) in preparation for adding trypsin, or another chemical-releasing agent to release any adherent cells. A reagent may be loaded into the system until the reagent bag is empty. The reagent may be chased into the IC loop, and the reagent may be mixed within the IC loop. Following the release of any adherent cells, harvest operation 830 transfers the cells in suspension from the IC circulation loop, including any cells remaining in the bioreactor, to a harvest bag. Finally, the disposable set is unloaded 832 from the cell expansion system, and process 800 then terminates at END operation 834.

Returning to query 804, if it is not desired to follow a schedule for feeding the cells, process 800 branches “no” to initiate the feeding of cells 818, in which a default or pre-programmed task for feeding the cells, e.g., “Feed Cells,” may be followed or a user or an operator, for example, may manually enter the inlet rates and other conditions to initiate feeding, according to embodiments. Next, glucose/lactate levels may be measured 820, in which a user or operator, for example, may measure such levels on a regular basis, e.g., daily, to determine adjustments 822, if any, to make to the amounts of media used for feeding the cells based on metabolite consumption and production. In embodiments, no adjustments may be desired, while in other embodiments, increases in inlet rates of media may be made in response to the measured glucose/lactate levels. In another embodiment, such glucose/lactate measurements may be taken at random time periods, depending on the user's or operator's preference, for example. In embodiments, such glucose/lactate levels are measured by taking a sample from a sample coil or sample port, such as an EC sample port, of a cell expansion system. In other embodiments, such glucose/lactate levels may be measured by taking a sample by splicing the IC loop of a cell expansion system using a sterile tubing welder, for example. Where adjustments to the inlet rates are desired, such adjustments may be made, and the cells may be fed accordingly 822 in amounts that account for the glucose/lactate levels measured at step 820. For example, the IC inlet rate may be increased two-fold when the glucose value falls below 70 mg/dL, according to an embodiment. The cells are allowed to grow or expand 824. The cells are not limited to growing or expanding at step 824, but, instead, the cells may also expand during the feeding step(s), for example. Next, query 826 determines whether it is desired to continue the monitoring of the glucose/lactate levels. If it is desired to continue such monitoring to allow for adjustments to the feeding rates, process 800 proceeds “yes” to measure glucose/lactate levels 820, and process 800 proceeds again to adjust the feeding of the cells accordingly 822 and the growing/expanding of the cells 824. If it is not desired to continue the monitoring of such glucose/lactate levels, process 800 proceeds “no” from query 826.

Next, attached cells may be released 828 from the membrane of the bioreactor and suspended in the IC loop, for example. In embodiments, an IC/EC washout task in preparation for adding a reagent to release the cells is performed as part of operation 828. For example, IC/EC media may be replaced with a phosphate buffered saline (PBS) to remove protein, calcium (Ca²⁺), and magnesium (Mg²⁺) in preparation for adding trypsin, or another chemical-releasing agent, to release any adherent cells. A reagent may be loaded into the system until the reagent bag is empty. The reagent may be chased into the IC loop, and the reagent may be mixed within the IC loop. Following the release of any adherent cells, harvest operation 830 transfers the cells in suspension from the IC circulation loop, including any cells remaining in the bioreactor, to a harvest bag. Finally, the disposable set is unloaded 832 from the cell expansion system, and process 800 then terminates at END operation 834.

With respect to the processes illustrated in FIGS. 7A, 7B, and 8 , the operational steps depicted are offered for purposes of illustration and may be rearranged, combined into other steps, used in parallel with other steps, etc., according to embodiments of the present disclosure. Fewer or additional steps may be used in embodiments without departing from the spirit and scope of the present disclosure. Also, steps (and any sub-steps), such as priming, coating a bioreactor, loading cells, for example, may be performed automatically in some embodiments, such as by a processor executing pre-programmed tasks stored in memory, in which such steps are provided merely for illustrative purposes.

Examples and further description of tasks and protocols, including custom tasks and pre-programmed tasks, for use with a cell expansion system are provided in U.S. patent application Ser. No. 13/269,323 (“Configurable Methods and Systems of Growing and Harvesting Cells in a Hollow Fiber Bioreactor System,” filed Oct. 7, 2011) and U.S. patent application Ser. No. 13/269,351 (“Customizable Methods and Systems of Growing and Harvesting Cells in a Hollow Fiber Bioreactor System,” filed Oct. 7, 2011), which are hereby incorporated by reference herein in their entireties for all that they teach and for all purposes.

Next, FIG. 9 illustrates example components of a computing system 900 upon which embodiments of the present disclosure may be implemented. Computing system 900 may be used in embodiments, for example, where a cell expansion system uses a processor to execute tasks, such as custom tasks or pre-programmed tasks performed as part of processes such as processes 700, 754, and 800 described above. In embodiments, a pre-programmed task may include, for example, follow “Scheduled Feed” for feeding cells per a specific schedule, such as a conservative, aggressive, or other type of schedule.

The computing system 900 may include a user interface 902, a processing system 904, and/or storage 906. The user interface 902 may include output device(s) 908, and/or input device(s) 910 as understood by a person of skill in the art. Output device(s) 908 may include one or more touch screens, in which the touch screen may comprise a display area for providing one or more application windows. The touch screen may also be an input device 910 that may receive and/or capture physical touch events from a user or operator, for example. The touch screen may comprise a liquid crystal display (LCD) having a capacitance structure that allows the processing system 904 to deduce the location(s) of touch event(s), as understood by those of skill in the art. The processing system 904 may then map the location of touch events to UI elements rendered in predetermined locations of an application window. The touch screen may also receive touch events through one or more other electronic structures, according to embodiments. Other output devices 908 may include a printer, speaker, etc. Other input devices 910 may include a keyboard, other touch input devices, mouse, voice input device, etc., as understood by a person of skill in the art.

Processing system 904 may include a processing unit 912 and/or a memory 914, according to embodiments of the present disclosure. The processing unit 912 may be a general purpose processor operable to execute instructions stored in memory 914. Processing unit 912 may include a single processor or multiple processors, according to embodiments. Further, in embodiments, each processor may be a multi-core processor having one or more cores to read and execute separate instructions. The processors may include general purpose processors, application specific integrated circuits (ASICs), field programmable gate arrays (FPGAs), other integrated circuits, etc., as understood by a person of skill in the art.

The memory 914 may include any short-term or long-term storage for data and/or processor executable instructions, according to embodiments. The memory 914 may include, for example, Random Access Memory (RAM), Read-Only Memory (ROM), or Electrically Erasable Programmable Read-Only Memory (EEPROM), as understood by a person of skill in the art. Other storage media may include, for example, CD-ROM, tape, digital versatile disks (DVD) or other optical storage, tape, magnetic disk storage, magnetic tape, other magnetic storage devices, etc., as understood by a person of skill in the art.

Storage 906 may be any long-term data storage device or component. Storage 906 may include one or more of the systems described in conjunction with the memory 914, according to embodiments. The storage 906 may be permanent or removable. In embodiments, storage 906 stores data generated or provided by the processing system 904.

EXAMPLES

Below are examples of methods or protocols that may be used with a cell expansion system, such as CES 500 (FIG. 5 ) and/or CES 600 (FIG. 6 ), for example, that implements features of the present disclosure. Such examples provide for scheduled feeds, e.g., IC inlet rate increases according to a schedule, for the expansion of cells. Such examples provide for the expansion of MSCs. Other cell types may be used in other embodiments.

It is noted that the example methods or protocols below are provided for illustrative purposes and are not intended to limit other embodiments, which may include different or additional steps, parameters, or other features. The example methods or protocols, including the steps (and any sub-steps), may be performed automatically in some embodiments, such as by a processor executing pre-programmed tasks stored in memory. In other embodiments, the steps (and any sub-steps) may be performed through the combination of automated and manual execution of operations. In further embodiments, the steps (and any sub-steps) are performed by an operator(s) or user(s) or through other manual means.

Example 1

This example relates to the Culture of Human Bone Marrow-Derived Mesenchymal Stem Cells on an Automated Cell Expansion System Using Scheduled IC Inlet Rate Increases. In this example, the protocol of Table 3 is used, and three different seeding densities are examined: 238 cells/cm² (5 million total load); 476 cells/cm² (10 million total load); and 952 cells/cm² (20 million total load). While Table 3 shows an example protocol that may be used with a cell expansion system, such as CES 500 (FIG. 5 ) or CES 600 (FIG. 6 ), that implements features of the present disclosure, it is noted that the example protocol is provided for illustrative purposes and is not intended to limit other embodiments, which may include different steps, parameters, or other features. The example protocol, including the steps (and any sub-steps) of priming the set, coating the bioreactor, loading cells, for example, may be performed automatically in some embodiments, such as by a processor executing pre-programmed tasks stored in memory.

In this example embodiment, a cell expansion set, or disposable tubing set, is loaded onto a cell expansion system. Next, the cell expansion set is primed. Such priming may occur by selecting a task for priming, in an embodiment. Such task for priming may be a pre-programmed task, for example. In this example, as shown in Table 3 below, the cell expansion system is primed with phosphate buffered saline (PBS). Next, the bioreactor is coated with a coating agent, such as fibronectin or cryoprecipitate in PBS. After coating the bioreactor, an IC/EC Washout task is performed, in which fluid on the IC and EC circulation loops is replaced with complete media, for example. In this example, media comprising alpha-MEM (a-MEM) and fetal bovine serum (FBS) is used. Next, the media is conditioned to maintain a desired gas concentration across the hollow fibers in the bioreactor membrane. Following the conditioning of media, cells are loaded into the bioreactor. For example, as shown in Table 3 below, the cells are loaded with uniform suspension. Next, cells, e.g., adherent cells, are allowed to attach to the hollow fibers. The cells are then fed according to the schedule shown in Table 4 below, “Example Feed Schedule.” See Table 4 below. Table 4 below includes both an “Aggressive” feed schedule and a “Control.” As shown in Table 4, the “Control” provides for measuring metabolite, e.g., glucose, levels and adjusting the IC inlet amount based on such measurements. See Table 4. Returning to the example protocol shown in Table 3, the cells are allowed to grow or expand. Next, an IC/EC Washout is performed. As shown in Table 3 for this example embodiment, IC media is replaced with phosphate buffered saline (PBS) in preparation for adding trypsin to release the cells. The attached cells are then released from a hollow fiber membrane of the bioreactor and suspended in the IC loop. Next, the cells are harvested using complete media. The cell expansion set is then unloaded.

TABLE 3 Example Pre-Selected MSC Expansion Protocol Day Task Media −1 Load Cell Expansion Set None Prime Cell Expansion Set PBS Coat Bioreactor FN or CPPT in PBS  0 IC EC Washout IC Inlet: Complete Media EC Inlet: Complete Media Condition Media IC Inlet: None EC Inlet: Complete Media Load Cells With Uniform IC Inlet: Complete Media Suspension EC Inlet: None Attach Cells (at 180°) IC Inlet: None EC Inlet: Complete Media 1 - Harvest Feed Cells (refer to Table 4) IC Inlet: Complete Media EC Inlet: None Harvest Release Adherent Cells IC/EC Washout with PBS then Trypsin Harvest Cells IC Inlet: Complete Media EC Inlet: Complete Media Unload Cell Expansion Set None

TABLE 4 Example Feed Schedule Day Control Aggressive Day 0 (Attach Cells) 0.1 mL/min EC Inlet 0.1 mL/min EC Inlet Day 1 (Feed Cells) 0.1 mL/min IC Inlet 0.1 mL/min IC Inlet Day 2 (Feed Cells) Double IC Inlet if 0.2 mL/min IC Inlet glucose below 70 mg/dL Day 3 (Feed Cells) Double IC Inlet if 0.4 mL/min IC Inlet glucose below 70 mg/dL Day 4 (Feed Cells) Double IC Inlet if 0.8 mL/min IC Inlet glucose below 70 mg/dL Day 5 (Feed Cells) Double IC Inlet if 1.2 mL/min IC Inlet glucose below 70 mg/dL Day 6 (Feed Cells) Double IC Inlet if 1.6 mL/min IC Inlet or glucose below 70 Harvest mg/dL Day 7 (Feed Cells or Double IC Inlet if 2.0 mL/min IC Inlet or Harvest) glucose below 70 Harvest mg/dL Estimated Media 1.5 L-4.8 L 6.4 L Usage (Calculated based on a 7-day expansion starting on Day 0 Attach Cells to Day 7 Harvest)

Results of following the Example Protocol in Table 3 and the Control Feed and Aggressive Feed Schedule of Table 4 are shown in Table 5 below, according to an embodiment. In Table 5, “Sch. Feed” refers to “Scheduled Feed.”

TABLE 5 Results for Control v. Aggressive Feed Schedule 5M Cell Load 10M Cell Load 20M Cell Load Harvest Doubling Doubling Doubling Day Number Times Number Number Times Number Number Times Number Culture of Cells (dT) of of Cells (dT) of of Cells (dT) of Condition Harvested (hours) Doublings Harvested (hours) Doublings Harvested (hours) Doublings Day 5 2.02E+08 26.6 4.3 2.34E+08 33.9 3.5 Control Day 5 2.38E+08 +/− 25.2 +/− 0.3 4.6 +/− 0.1 3.85E+08 +/− 28.1 +/− 0.7 4.3 +/− 0.1 Sch. Feed 9.45E+06 2.81E+07 Day 6 2.03E+08 26.1 5.3 2.59E+08 29.7 4.7 4.07E+08 33.1 4.3 Control Day 6 2.50E+08 24.7 5.6 3.55E+08 +/− 27.1 +/− 0.7 5.1 +/− 0.1 5.78E+08 +/− 29.7 +/− 0.6 4.9 +/− 0.1 Sch. Feed 3.33E+07 3.91E+07 Day 7 2.19E+08 29.9 5.5 3.72E+08 31.3 5.2 4.45E+08 37.5 4.5 Control Day 7 4.11E+08 +/− 25.7 +/− 0.4 6.4 +/− 0.1 2.84E+08 +/− 33.9 +/− 1.2 4.8 +/− 0.1 1.66E+08 +/− 55.6 +/− 5.6 3.1 +/− 0.4 Sch. Feed 3.01E+07 3.37E+07 3.48E+07 N = 2 for all runs except Day 5, Day 6, and 7 Controls and 5M Cell Load Day 6 Scheduled Feed, where N is the number of machines used per load condition, e.g., number of cells loaded and harvest day, according to embodiments.

Further, FIG. 10 presents a graphical representation 1000 of the data (see Table 5) for “Doubling Times for a Control Feed versus an Aggressive Feed” based on following the Example Protocol in Table 3 with the parameters of Table 4. The y-axis 1002 of FIG. 10 displays the doubling time (dT) for cells in hours for the Control Feed 1004 and for the Aggressive Feed 1006. The x-axis 1008 displays the Time in Culture in days for the Control Feed 1004 and for the Aggressive Feed 1006. Such results are provided for cell loads of 5 million total load (5M), 10 million total load (10M), and 20 million total load (20M), as indicated on the x-axis 1008. As shown in Table 5 and FIG. 10 , results are provided for the Doubling Times for Control versus Aggressive Feed at 1010 (5M, 6 Days); 1012 (5M, 7 Days); 1014 (10M, 5 Days); 1016 (10M, 6 Days); 1018 (10M, 7 Days); 1020 (20M, 5 Days); 1022 (20M, 6 Days); and 1024 (20M, 7 Days).

Next, FIG. 11 shows a graphical representation 1100 of the data (see Table 5) for “Number of Cells Harvested for a Control Feed versus an Aggressive Feed” based on following the Example Protocol in Table 3 with the parameters of Table 4. The y-axis 1102 of FIG. 11 displays the Number of Cells Harvested (10⁶) for the Control Feed 1104 and for the Aggressive Feed 1106. The x-axis 1108 displays the Time in Culture in days for the Control Feed 1104 and for the Aggressive Feed 1106. Such results are provided for cell loads of 5 million total load (5M), 10 million total load (10M), and 20 million total load (20M), as indicated on the x-axis 1108. As shown in Table 5 and FIG. 11 , results are provided for the Number of Cells Harvested for Control versus Aggressive Feed at 1110 (5M, 6 Days); 1112 (5M, 7 Days); 1114 (10M, 5 Days); 1116 (10M, 6 Days); 1118 (10M, 7 Days); 1120 (20M, 5 Days); 1122 (20M, 6 Days); and 1124 (20M, 7 Days).

As shown in Table 5 and FIGS. 10 and 11 , implementing the aggressive feed schedule of Table 4 during a bone marrow-derived MSC expansion may result in higher cell harvest yield in some instances, according to an embodiment. As shown, the aggressive feed schedule may result in some instances in about a 20% increase in cell yield as compared to the control feed method, except for the 10M and 20M loads expanded for seven (7) days, according to an embodiment. The lower cell yields for the aggressive feed schedule as compared to the control feed method at 1118 (10M, 7 Days) and 1124 (20M, 7 Days) may be due to over-confluence. Media usage may also be more predictable. Flow cytometry results for the control and aggressive feed schedules indicate that the cells may maintain MSC phenotype (data not shown). In an embodiment, little or no aggregation may be observed in the harvest products with high viability (>97%). Morphological characterization of MSC may also be observed on representative harvest products, according to an embodiment.

Example 2

This example relates to the Culture of Human Bone Marrow-Derived Mesenchymal Stem Cells on an Automated Cell Expansion System Using Scheduled IC Inlet Rate Increases. In this example, the protocol of Table 6 is used, and three different seeding densities are examined: 238 cells/cm² (5 million total load), 476 cells/cm² (10 million total load), and 952 cells/cm² (20 million total load). While Table 6 shows an example protocol that may be used with a cell expansion system, such as CES 500 (FIG. 5 ) or CES 600 (FIG. 6 ), that implements features of this disclosure, it is noted that the example protocol is provided for illustrative purposes and is not intended to limit other embodiments, which may include different steps, parameters, or other features. The example protocol, including the steps (and any sub-steps) of priming the set, coating the bioreactor, loading cells, for example, may be performed automatically in some embodiments, such as by a processor executing pre-programmed tasks stored in memory.

In this example embodiment, a cell expansion set, or disposable tubing set, is loaded onto a cell expansion system. Next, the cell expansion set is primed. Such priming may occur by selecting a task for priming. Such task for priming may be a pre-programmed task, for example. In this example, as shown in Table 6 below, the cell expansion system is primed with phosphate buffered saline (PBS). Next, the bioreactor is coated with a coating agent, such as fibronectin or cryoprecipitate in PBS. After coating the bioreactor, an IC/EC Washout task is performed, in which fluid on the IC and EC circulation loops is replaced with complete media, for example. Next, the media is conditioned to maintain a desired gas concentration across the hollow fibers in the bioreactor membrane. Following the conditioning of media, cells are loaded into the bioreactor. For example, as shown in Table 6 below, the cells are loaded with uniform suspension. Next, cells, e.g., adherent cells, are allowed to attach to the hollow fibers. The cells are then fed according to the schedule shown in Table 7 below, “Example Feed Schedule.” See Table 7 below. Table 7 below includes both a “Conservative” feed schedule and a “Control.” As shown in Table 7, the “Control” provides for measuring metabolite, e.g., glucose, levels and adjusting the IC inlet amount based on such measurements. See Table 7 below. Returning to the example protocol shown in Table 6, the cells are allowed to grow or expand. Next, an IC/EC Washout is performed. As shown in Table 6 for this example embodiment, IC media is replaced with PBS in preparation for adding trypsin to release the cells. The attached cells are then released from a hollow fiber membrane of the bioreactor and suspended in the IC loop, for example. Next, the cells are harvested using complete media. The cell expansion set is then unloaded.

TABLE 6 Example Pre-Selected MSC Expansion Protocol Day Task Media −1 Load Cell Expansion Set None Prime Cell Expansion Set PBS Coat Bioreactor FN or CPPT in PBS  0 IC EC Washout IC Inlet: Complete Media EC Inlet: Complete Media Condition Media IC Inlet: None EC Inlet: Complete Media Load Cells With Uniform IC Inlet: Complete Media Suspension EC Inlet: None Attach Cells (at 180°) IC Inlet: None EC Inlet: Complete Media 1 - Harvest Feed Cells (refer to Table 2) IC Inlet: Complete Media EC Inlet: None Harvest Release Adherent Cells IC/EC Washout with PBS then Trypsin Harvest Cells IC Inlet: Complete Media EC Inlet: Complete Media Unload Cell Expansion Set None

TABLE 7 Example Feed Schedule Day Control Conservative Day 0 (Attach Cells) 0.1 mL/min EC Inlet 0.1 mL/min EC Inlet Day 1 (Feed Cells) 0.1 mL/min IC Inlet 0.1 mL/min IC Inlet Day 2 (Feed Cells) Double IC Inlet if 0.2 mL/min IC Inlet glucose below 70 mg/dL Day 3 (Feed Cells) Double IC Inlet if 0.3 mL/min IC Inlet glucose below 70 mg/dL Day 4 (Feed Cells) Double IC Inlet if 0.5 mL/min IC Inlet glucose below 70 mg/dL Day 5 (Feed Cells) Double IC Inlet if 0.8 mL/min IC Inlet glucose below 70 mg/dL Day 6 (Feed Cells) Double IC Inlet if 1.0 mL/min IC Inlet or glucose below 70 Harvest mg/dL Day 7 (Feed Cells or Double IC Inlet if 1.2 mL/min IC Inlet or Harvest) glucose below 70 Harvest mg/dL Estimated Media 1.5 L-4.8 L 4.4 L Usage (Calculated based on a 7-day expansion starting on Day 0 Attach Cells to Day 7 Harvest)

Results of following the Example Protocol in Table 6 and the Control Feed and Conservative Feed Schedule of Table 7 are shown in Table 8 below, according to an embodiment. In Table 8, “Sch. Feed” refers to “Scheduled Feed.”

TABLE 8 Results for Control v. Conservative Feed Schedule 5M Cell Load 10M Cell Load 20M Cell Load Harvest Doubling Doubling Doubling Day Number Times Number Number Times Number Number Times Number Culture of Cells (dT) of of Cells (dT) of of Cells (dT) of Condition Harvested (hours) Doublings Harvested (hours) Doublings Harvested (hours) Doublings Day 6 2.42E+08 31.3 4.6 Control Day 6 2.15E+08 +/− 32.6 +/− 4.4 +/− Sch. Feed 2.01E+07 1.0 0.1 Day 7 2.76E+08 29.0 5.8 3.93E+08 38.5 4.3 Control Day 7 2.75E+08 +/− 29.1 +/− 0.2 5.8 +/− 0.0 3.90E+08 +/− 38.7 +/− 1.1 4.3 +/− 0.1 Sch. Feed 7.28E+06 3.50E+07 Day 8 4.07E+08 26.5 6.3 Control Day 8 4.20E+08 +/− 26.3 +/− 0.6 6.4 +/− 0.1 Sch. Feed 3.97E+07 N = 1 for all control runs and N = 2 for all scheduled feed runs where N is the number of machines used per load condition, e.g., number of cells loaded and harvest day, according to embodiments.

Further, FIG. 12 presents a graphical representation 1200 of the data (see Table 8) for “Doubling Times for a Control Feed versus a Conservative Feed” based on following the Example Protocol in Table 6 with the parameters of Table 7. The y-axis 1202 of FIG. 12 displays the doubling time (dT) for cells in hours for the Control Feed 1204 and for the Conservative Feed 1206. The x-axis 1208 displays the Time in Culture in days for the Control Feed 1204 and for the Conservative Feed 1206. Such results are provided for cell loads of 5 million total load (5M), 10 million total load (10M), and 20 million total load (20M), as indicated on the x-axis 1208. As shown in Table 8 and FIG. 12 , results are provided for the Doubling Times for Control versus Conservative Feed at 1210 (5M, 7 Days); 1212 (5M, 8 Days); 1214 (10M, 6 Days); and 1216 (20M, 7 Days).

Next, FIG. 13 presents a graphical representation 1300 of the data (see Table 8) for “Number of Cells Harvested for Control versus Conservative Feed” based on following the Example Protocol in Table 6 with the parameters of Table 7. The y-axis 1302 of FIG. 13 displays the Number of Cells Harvested (10⁶) for the Control Feed 1304 and for the Conservative Feed 1306. The x-axis 1308 displays the Time in Culture in days for the Control Feed 1304 and for the Conservative Feed 1306. Such results are provided for cell loads of 5 million total load (5M), 10 million total load (10M), and 20 million total load (20M), as indicated on the x-axis 1308. As shown in Table 8 and FIG. 13 , results are provided for the Number of Cells Harvested for Control versus Conservative Feed at 1310 (5M, 7 Days); 1312 (5M, 8 Days); 1314 (10M, 6 Days); and 1316 (20M, 7 Days).

As shown in Table 8 and FIGS. 12 and 13 , implementing the conservative feed schedule of Table 7 during a bone marrow-derived MSC expansion may result in a comparable cell harvest yield in some instances, according to an embodiment. As shown above, the conservative feed schedule may yield somewhat similar harvest numbers as the control feed in some instances but without the need for daily monitoring, in an embodiment. Media usage may also be more predictable. Flow cytometry results for the control and conservative feed schedules indicate that the cells may maintain MSC phenotype (data not shown). In an embodiment, little or no aggregation may be observed in the harvest products with high viability (>97%). Morphological characterization of MSC may also be observed on representative harvest products, according to an embodiment.

Further, in comparing Examples 1 and 2, the data for Example 2 in Table 8 may show the use of less media than the amount of media used in the aggressive feed schedule of Example 1.

It will be apparent to those skilled in the art that various modifications may be made to the apparatus, systems, structure, methods, and protocols described herein. Thus, it should be understood that the embodiments are not limited to the specific examples given. Various modifications, changes, and variations apparent to those skilled in the art may be made in the arrangement, operation, and details of the methods and systems of the present disclosure without departing from the scope of the invention. 

What is claimed is:
 1. A method of feeding cells in a cell expansion system according to a schedule, the method comprising: coating a bioreactor; loading cells into the bioreactor; feeding the cells at a first inlet rate during a first time period; feeding the cells at a second inlet rate during a second time period, wherein the feeding of the cells at the second inlet rate comprises increasing the first inlet rate by a first percentage of the first inlet rate; and feeding the cells at a third inlet rate during a third time period, wherein the feeding of the cells at the third inlet rate comprises increasing the second inlet rate by a second percentage of the second inlet rate.
 2. The method of claim 1, wherein the portion of the cell expansion system comprises an intracapillary (IC) portion of the cell expansion system.
 3. The method of claim 1, wherein the portion of the cell expansion system comprises an extracapillary (EC) portion of the cell expansion system.
 4. The method of claim 2, wherein the intracapillary (IC) portion of the cell expansion system comprises an intracapillary (IC) circulation loop.
 5. The method of claim 3, wherein the extracapillary (EC) portion of the cell expansion system comprises an extracapillary (EC) circulation loop.
 6. The method of claim 1, wherein the cell expansion system comprises a closed system.
 7. The method of claim 1, wherein the first percentage and the second percentage are the same.
 8. The method of claim 7, wherein the first percentage and the second percentage are each equal to or greater than about 100%. 